Chris Pratt embarking on 21-day Daniel Fast, a Bible-inspired diet

Chris Pratt at the 2018 MTV Movie And TV Awards at Barker Hangar on June 16, 2018, in Santa Monica, California.

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Most diets are focused on weight loss, but Chris Pratt‘s wellness regime has a higher purpose.

In a video posted to Instagram on Thursday, the 39-year-old actor revealed he is on the “Daniel Fast” — a Bible-inspired diet that supposedly brings you closer to God.

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“Hi, Chris Pratt here. Day three of the Daniel Fast,” he said in a now-expired Instagram story. “Check it out, it’s 21 days of prayer and fasting. It’s going to coincide also, coincidentally, with the Lego Movie 2 junkets, so by the time you see me, I’ll probably be hallucinating. Stay tuned.”

The Daniel Fast is based on the fasting experiences of the Old Testament prophet, Daniel, and typical Jewish fasting principles, said Susan Gregory, founder of Daniel-Fast.com.

It’s a partial fast, in which people are only able to eat foods grown from seed and drink water. Meats, dairy and all processed foods are not allowed.

Gregory said that the fast “puts your whole being on alert” and brings your focus to God.

“When you’re changing the foods that you eat… you’re crossing over into a different way of behaving in a similar way of when you go on a vacation: you’re thinking differently, you’re preparing differently, you’re acting differently,” she said.

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“The same thing happens when you enter into a spiritual fast.”

Gregory said people usually have a purpose to their fast, whether it’s learning to pray more, lose weight or work through personal hardship.

While Pratt has not identified his specific reason for the fast, he recently shared his desire to improve his health in 2019.

“God is real. God loves you. God wants the best for you. Believe that. I do,” he said. “Learn to pray. It’s easy and it’s so good for your soul.”

While working towards health goals is normal, Abby Langer, a Toronto-based registered dietitian and nutritionist, said there’s no physiological reason to go on a Daniel Fast.

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“It shouldn’t be harmful unless you have a condition like diabetes, are pregnant or have an eating disorder, but I don’t recommend it,” she told Global News.

“When you fast in this sort of way, you will lose weight, but a lot of that weight is water and muscle so what will happen is as soon as you go off this fast, you’re going to put all the weight back on and you’d have lost muscle — which is really detrimental to your health.”

During the 21 days, Langer said people will experience a change in energy levels, and their daily functioning will be affected.

“You’re probably going to feel really, really tired, be in a bad mood and probably not be able to effectively go about your daily activities, and you’ll certainly find it difficult to work out,” she said.

On top of not being a healthy or sustainable way to lose weight, Langer said there are emotional dangers to fasting, too.

“There’s no healthy reason to want to do something like this. It can be very damaging emotionally, especially for people who are predisposed to or have a history of eating disorders, as it can trigger disordered eating,” she explained.